carb sizes and choice

I've been wondering lately... With all the various carb sizes available, how do you guys determine what size to use? I've heard of people going from a stock 14:12 to a 15, to a 19, or a 20 or 21. Why, when you could get a 19, would anyone "upgrade" to a 15? Or why even use a 19 at all, when there's a 20? Or why not just go straight to a 21? Seems like using those smaller carbs is an unnecessary middle step, and not really much of an upgrade... or am I missing something?

Re: carb sizes and choice

bigger is not always better. Bigger carbs are useless unless the intake port on your cylinder is big enough. Generally you want the biggest carb you cylinder port allows. Any bigger is pointless and is harder to tune. Some people of course like the smaller carbs because the 15 bing and SHA are 1 jet carbs, so they are easier to tune.

Re: carb sizes and choice

not only easier to tune, but running a 14mm carb on my Maxi gets me 45mph with my 64 polini, and I'm fine with that speed. the faster you go, the quicker your parts wear out. My budget likes things that last longer.

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